# Copyright (C) 2022 The Qt Company Ltd.
# SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
from __future__ import annotations

"""PySide6 port of the widgets/desktop/screenshot example from Qt v6.x"""

import sys

from PySide6.QtCore import (QDir, QPoint, QRect, QStandardPaths, Qt, QTimer,
                            Slot)
from PySide6.QtGui import QGuiApplication, QImageWriter
from PySide6.QtWidgets import (QApplication, QCheckBox, QDialog, QFileDialog,
                               QGridLayout, QGroupBox, QHBoxLayout, QLabel,
                               QMessageBox, QPushButton, QSizePolicy, QSpinBox,
                               QVBoxLayout, QWidget)


class Screenshot(QWidget):
    def __init__(self):
        super().__init__()

        self.screenshot_label = QLabel(self)

        self.screenshot_label.setSizePolicy(QSizePolicy.Expanding, QSizePolicy.Expanding)
        self.screenshot_label.setAlignment(Qt.AlignCenter)

        screen_geometry: QRect = self.screen().geometry()
        self.screenshot_label.setMinimumSize(
            screen_geometry.width() / 8, screen_geometry.height() / 8
        )

        main_layout = QVBoxLayout(self)
        main_layout.addWidget(self.screenshot_label)

        options_group_box = QGroupBox("Options", self)
        self.delay_spinbox = QSpinBox(options_group_box)
        self.delay_spinbox.setSuffix(" s")
        self.delay_spinbox.setMaximum(60)

        self.delay_spinbox.valueChanged.connect(self.update_checkbox)

        self.hide_this_window_checkbox = QCheckBox("Hide This Window", options_group_box)

        options_group_box_layout = QGridLayout(options_group_box)
        options_group_box_layout.addWidget(QLabel("Screenshot Delay:", self), 0, 0)
        options_group_box_layout.addWidget(self.delay_spinbox, 0, 1)
        options_group_box_layout.addWidget(self.hide_this_window_checkbox, 1, 0, 1, 2)

        main_layout.addWidget(options_group_box)

        buttons_layout = QHBoxLayout()
        self.new_screenshot_button = QPushButton("New Screenshot", self)
        self.new_screenshot_button.clicked.connect(self.new_screenshot)
        buttons_layout.addWidget(self.new_screenshot_button)
        save_screenshot_button = QPushButton("Save Screenshot", self)
        save_screenshot_button.clicked.connect(self.save_screenshot)
        buttons_layout.addWidget(save_screenshot_button)
        quit_screenshot_button = QPushButton("Quit", self)
        quit_screenshot_button.setShortcut(Qt.CTRL | Qt.Key_Q)
        quit_screenshot_button.clicked.connect(self.close)
        buttons_layout.addWidget(quit_screenshot_button)
        buttons_layout.addStretch()
        main_layout.addLayout(buttons_layout)

        self.shoot_screen()
        self.delay_spinbox.setValue(5)

        self.setWindowTitle("Screenshot")
        self.resize(300, 200)

    def resizeEvent(self, event):
        scaled_size = self.original_pixmap.size()
        scaled_size.scale(self.screenshot_label.size(), Qt.KeepAspectRatio)
        if scaled_size != self.screenshot_label.pixmap().size():
            self.update_screenshot_label()

    @Slot()
    def new_screenshot(self):
        if self.hide_this_window_checkbox.isChecked():
            self.hide()
        self.new_screenshot_button.setDisabled(True)

        QTimer.singleShot(self.delay_spinbox.value() * 1000, self.shoot_screen)

    @Slot()
    def save_screenshot(self):
        fmt = "png"  # In order to avoid shadowing built-in format
        initial_path = QStandardPaths.writableLocation(QStandardPaths.PicturesLocation)
        if not initial_path:
            initial_path = QDir.currentPath()
        initial_path += f"/untitled.{fmt}"

        fileDialog = QFileDialog(self, "Save As", initial_path)
        fileDialog.setAcceptMode(QFileDialog.AcceptSave)
        fileDialog.setFileMode(QFileDialog.AnyFile)
        fileDialog.setDirectory(initial_path)
        mime_types = []

        for bf in QImageWriter.supportedMimeTypes():
            mime_types.append(bf.data().decode("utf8"))
        fileDialog.setMimeTypeFilters(mime_types)
        fileDialog.selectMimeTypeFilter("image/" + fmt)
        fileDialog.setDefaultSuffix(fmt)
        if fileDialog.exec() != QDialog.Accepted:
            return

        file_name = fileDialog.selectedFiles()[0]
        if not self.original_pixmap.save(file_name):
            path = QDir.toNativeSeparators(file_name)
            QMessageBox.warning(
                self,
                "Save Error",
                f"The image could not be saved to {path}.",
            )

    def shoot_screen(self):
        screen = QGuiApplication.primaryScreen()
        window = self.windowHandle()
        if window:
            screen = window.screen()
        if not screen:
            return

        if self.delay_spinbox.value() != 0:
            QApplication.beep()

        self.original_pixmap = screen.grabWindow(0)
        self.update_screenshot_label()

        self.new_screenshot_button.setDisabled(False)
        if self.hide_this_window_checkbox.isChecked():
            self.show()

    @Slot()
    def update_checkbox(self):
        if self.delay_spinbox.value() == 0:
            self.hide_this_window_checkbox.setDisabled(True)
            self.hide_this_window_checkbox.setChecked(False)
        else:
            self.hide_this_window_checkbox.setDisabled(False)

    def update_screenshot_label(self):
        self.screenshot_label.setPixmap(
            self.original_pixmap.scaled(
                self.screenshot_label.size(),
                Qt.KeepAspectRatio,
                Qt.SmoothTransformation,
            )
        )


if __name__ == "__main__":
    app = QApplication(sys.argv)
    screenshot = Screenshot()
    screenshot.move(screenshot.screen().availableGeometry().topLeft() + QPoint(20, 20))
    screenshot.show()
    sys.exit(app.exec())
